The passenger side airbag module assembly for a motor vehicle normally includes a trough-shaped reaction canister which holds the folded airbag and is installed behind the dash board. An inflator housing is associated with the reaction canister and encloses a gas generant normally contained, in turn, within a cylindrical filter pack. The filter pack is a steel mesh material retained within the inflator housing by a base or bases. These bases are normally installed by welding, or swaging the inflator housing around their ends. Upon the occurence of a collision of sufficient magnitude, the generator is ignited and gases from the burning charge pass through openings in the inflator housing to inflate the airbag.
Airbag modules constructed in accordance with the prior art have certain deficiencies which it would be desirable to overcome. Many of these deficiencies relate to the end bases which close the inflator housing. Conventionally, these bases require a seal between the base and the filter pack and diameters that fit tight in the inflator housing for centering. These filter packs in turn require a sizing operation to control their diameter tolerance for installation in the inflator housing.
Another problem arises where seals between the bases and filter pack are used. There is a tendency for the seal to off-gas causing flaming subsequent to airbag actuation.
A further problem arises from the need for an auto ignition charge within the inflator. The purpose of this charge is to set off the main gas generant causing the inflator to function early, in the event of a warehouse or vehicle fire, at a temperature where the inflator housing and reaction canister still retain their structural integrity. This requires good heat transfer to the auto ignition charge and good access of the ignited auto ignition charge to the inflator igniter. To that effect, it would be desirable to improve the heat transfer characteristics from the outer wall to the auto ignition charge.
Accordingly, it is a primary object of the present invention to provide an end base construction which is not orientation critical. Another object is to provide such a construction wherein sealing is improved without the need for O-rings. Another object is to provide such a construction wherein the ends of the filter pack are removed from the gas path. Another object is to provide such a construction wherein the heat transmission characteristics from the outer wall of the inflator housing to the internally housed auto ignition charge is improved. Other objects, features and advantages will become apparent from the following description and appended claims.